1. Department of Epidemiology, Graduate School of Public Health, Seoul National University, Seoul, Korea.
2. Department of Emergency Medical Service Management, Seoul Metropolitan Fire and Disaster Headquarters, Seoul, Korea.
3. Department of Emergency Medicine, Inje University, Seoul Paik Hospital, Seoul, Korea.
4. Department of Emergency Medicine, Seoul National University Hospital, Seoul, Korea.
5. Department of Emergency Medicine, DongGuk University Ilsan Hospital, Goyang, Korea.
6. Seoul National University Hospital Biomedical Research Institute, Seoul, Korea.